use 2021 edition (#1084)

jimexist · jimexist · commit 315dc6f6e2f6 · 2021-12-31T10:14:08.000+08:00
GitOrigin-RevId: b020aba079ae89366b1b6a2b0ed7e8409f99f0d9
diff --git a/Cargo.toml b/Cargo.toml
@@ -24,7 +24,8 @@ authors = ["Apache Arrow <dev@arrow.apache.org>"]
 description = "Build and run queries against data"
 readme = "README.md"
 license = "Apache-2.0"
-edition = "2018"
+edition = "2021"
+rust-version = "1.56"
 
 [dependencies]
 libc = "0.2"
diff --git a/rust-toolchain b/rust-toolchain
@@ -1 +1 @@
-nightly-2021-09-07
+nightly-2021-10-21
